.container {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  font-family: 'Microsoft YaHei', 'Verdana', 'Roboto', 'Helvetica Neue', Helvetica, Arial, sans-serif;
}
.main {
  width: 100%;
  display: flex;
  justify-content: center;
}

.chessboard {
  display: flex;
  position: relative;
}